Boaters biggest threat to Florida manatees

While hurricanes, stress and red tide poisoning threaten manatees, their greatest danger is from watercraft, accounting for about 25 percent of manatee deaths, said John Jett, who conducted the study for his doctoral dissertation, the Gainesville, Fla., school said in a news release.

"Although boaters across the board had strong conservation attitudes and thought manatees were worth saving, they created one of the biggest threats to manatees by not following the speed limit," Jett said.

Jett used a stopwatch and laser rangefinder to calculate speeds of boats traveling between two points along the St. Johns River near Blue Springs State Park during August, September and October last year. He recorded boat registration numbers and followed up with mail surveys that asked operators about their speeds and attitudes toward manatee conservation.

Boaters who admitted speeding listed not being able to read the signs clearly as the top reason, followed by escaping the rain, the study found.

"A lot of the boaters I talked to said they weren't sure how fast they were supposed to go," he said.